The earlier lagunas + clio's for that matter always had condensation inside. In fact the handbook even tells you this is normal.
However as you two have quite rightly pointed out it leads ( over time ) to a greenish slime build up on the inside of the light.
If your silver reflectors have been effected there's a high chance that bateria and the like have damaged this reflective coating neccesitating a replacement unit ( these can be found on
or from breakers from anywhere between £5 - 35 each )
As for removing them to clean I am afraid I have no clue.
Mr Haynes does sell a manual for the laguna I Phase 1 + Phase 2 however.